Elongated roller side seals for a rotary engine

ABSTRACT

A rotary engine 1 includes a side housing 2, an intermediate housing 12, a rotor housing 3, a rotor 4 accommodated rotatably in the rotor housing 3; side seal grooves 6 formed on both side surfaces 5 and 25 of the rotor 4; springs 8 for urging side seals 7 fitted respectively in the side seal grooves 6 toward the side housing 2 and the intermediate housing 12, and flexible linear rollers 10 each accommodated between a side wall surface 9 of the side seal groove 6 and the side seal 7.

TECHNICAL FIELD

The present invention relates to an internal combustion engine, and moreparticularly to a rotary engine.

BACKGROUND ART

A rotary engine used in an automobile or the like comprises a rotorhousing; a side housing and an intermediate housing arranged in such amanner as to sandwich the rotor housing from both sides thereof; a rotoraccommodated rotatably in the rotor housing; side seal grooves formedrespectively on both side surfaces of the rotor facing the side housingand the intermediate housing; side seals accommodated respectively inthe side seal grooves; and apex seals disposed at apexes of the rotor.

In the side seals of the rotary engine, end faces thereof at positionsprojecting from the side seal grooves are urged toward and are made toslidably abut against the side housing and the intermediate housing thatface the end faces, respectively, by means of springs accommodated inthe side seal grooves, thereby attaining primary gastightness withrespect to an engine operating chamber. The rotor axis-side sidesurfaces of the side seals are urged toward and are made to slidablyabut against side wall surfaces of the side seal grooves facing thoserespective side surfaces by means of gas pressure and the like, therebyattaining secondary gastightness with respect to the engine operatingchamber.

Since the side seal has a long length, and distances from the rotorcenter to respective positions thereof differ, the magnitudes anddirections of sliding resistance and inertial force at the respectivepositions thereof differ respectively. For this reason, each side sealabuts against the side wall surface of the side seal groove in anunnatural posture. In addition, the frictional resistance of contactbetween the side seal and the side wall surface of the side seal grooveis large (which is considered to be 0.1 to 0.3 in terms of a coefficientof friction), and even if the side seal is subjected to a lifting forceby the gas pressure inside the side seal groove when the side seal ispressed against the side wall surface of the side seal groove by the gaspressure from the engine operating chamber, the behavior of the sideseal is poor, and the sliding contact of the side seal with respect tothe side housing is not established sufficiently. For this reason,high-temperature gases burst out from the gap between the side seal andthe side housing, thereby resulting in the overheating of the rotaryengine and causing damage to a rotor oil seal. This overheating of therotary engine causes deformation of the rotary engine, i.e., deformationof the side housing, thereby resulting in a vicious circle of bringingabout further gas leakage.

In particular, combustion gases leaking from the side seal circulate tothe intake side and are sucked in by being mixed with a fresh intakegas, thereby constituting a cause of misfiring and resulting in adecline in output.

The present invention has been devised in view of the above-describedaspects, and its object is to provide a rotary engine which increasesthe mobility of each side seal in the side seal groove toward thesliding surfaces of the side housing and the intermediate housing so asto prevent a gap from being formed between an end face of the side sealand the respective sliding surfaces of the side housing and theintermediate housing, thereby making it possible to attain primarygastightness more reliably without deteriorating secondary gastightness.

DISCLOSURE OF INVENTION

In accordance with the present invention, the above-described object isattained by a rotary engine comprising: a rotor housing; a side housingand an intermediate housing arranged in such a manner as to sandwich therotor housing from both sides thereof; a rotor accommodated rotatably inthe rotor housing; a side seal groove formed on each of both sidesurfaces of the rotor facing the side housing and the intermediatehousing; side seals each accommodated in the side seal groove; springsfor pressing the side seals against the side housing and theintermediate housing, respectively; and a linear roller accommodatedalong the side seal between a side wall surface of the side seal grooveand the side seal.

In addition, the above-described object is also attained by a rotaryengine comprising: a side housing; a rotor housing; a rotor accommodatedrotatably in the rotor housing; a side seal groove formed on a sidesurface of the rotor facing the side housing; a side seal accommodatedin the side seal groove; a spring for urging the side seal against theside housing; and at least one linear roller accommodated between a sidewall surface of the side seal groove and the side seal along the sideseal.

In one aspect of the present invention, a groove is formed on a rotoraxis-side side surface of the side seal, and the linear roller isaccommodated in the groove. In another example, a stepped portion isformed on a rotor axis-side side surface of the side seal, and thelinear roller is accommodated in a recess of the stepped portion.

In addition, in the present invention, a thin steel sheet against whichthe linear roller abuts may be attached on a side wall surface of theside seal groove facing a rotor axis-side side surface of the side seal.A groove for accommodating the linear roller may be formed in this thinsteel sheet.

In the present invention, one linear roller may be used, but a pluralityof linear rollers may be arranged in parallel, or a plurality of linearrollers may be arranged in series. In a case where a plurality of linearrollers are arranged in parallel and in series, if positions of opposingends of the linear rollers in adjacent two rows of the linear rollersare made mutually different, it is possible to prevent a decline ingastightness.

In the rotary engine of the present invention, the side sealaccommodated in the side seal is urged by the spring, and its end faceis brought into slidable contact with the side housing. The side sealbehaves lightly and speedily through linear contact or rolling contactbetween the linear roller and the side seal groove, so that the slidingcontact of the side seal with respect to the sliding surfaces of theside housing and the intermediate housing is effected reliably, therebysecuring sufficient gastightness.

As described above, in accordance with the present invention, thesliding contact of the side seal with respect to the sliding surfaces ofthe side housing and the intermediate housing is improved, it ispossible to reliably prevent leakage of combustion gases and the like,primary gastightness can be maintained reliably, the overheating of theengine, misfiring and the like can be prevented, and the output can beimproved.

Hereafter, a more detailed description of the present invention will begiven on the basis of specific examples shown in the drawings. Hence,the above object and features as well as other objects and features ofthe present invention will become more apparent. It should be noted thatthe present invention is not restricted to these specific examples.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view of a preferred embodiment of thepresent invention;

FIG. 2 is a side elevational view of a rotor and the like shown in FIG.1;

FIG. 3 is a cross-sectional view taken along line III--III shown in FIG.2;

FIG. 4 is a detailed perspective view of linear rollers and a side sealshown in FIG. 2;

FIG. 5 is a cross-sectional view of another preferred embodiment of thepresent invention;

FIG. 6 is a side elevational view of the rotor and the like shown inFIG. 5;

FIG. 7 is a cross-sectional view taken along line IIV--IIV shown in FIG.6;

FIG. 8 is a side elevational view of the rotor in accordance withanother preferred example of the present invention;

FIG. 9 is a partial cross-sectional view of still another preferredembodiment of the present invention;

FIG. 10 is a cross-sectional view of a further preferred embodiment ofthe present invention;

FIG. 11 is a detailed explanatory cross-sectional view of linearrollers, a side seal, and the like shown in FIG. 10;

FIG. 12 is a cross-sectional view of a still further preferredembodiment of the present invention; and

FIG. 13 is a detailed perspective view of linear rollers and a side sealin accordance with a further preferred embodiment of the presentinvention.

EMBODIMENTS

In FIGS. 1 to 4, a rotary engine 1 of this embodiment comprises a sidehousing 2; an intermediate housing 12; a rotor housing 3; a rotor 4accommodated rotatably in the rotor housing 3; arcuate side seal grooves6 formed on both side surfaces 5 and 25 of the rotor 4 which arerespectively arranged in face-to-face relation with the side housing 2and the intermediate housing 12; side seals 7 accommodated respectivelyin the side seal grooves 6; springs 8 for urging the side seals 7 towardthe side housing 2 and the intermediate housing 12, respectively; and atleast one flexible linear roller 10 disposed between a side wall surface9 in the side seal groove 6 and the side seal 7 and accommodated alongthe side seal 7, three flexible linear rollers 10 being provided inparallel in this embodiment. The side housing 2 and the intermediatehousing 12 are disposed in such a manner as to sandwich the rotorhousing 3 from both sides thereof.

It should be noted that the side seal grooves 6, the side seals 7, andthe like are formed in substantially the same manner on both the sidehousing 2 side and the intermediate housing 12 side. In the descriptionthat follows, a detailed description will be given of the side housing 2side, and the intermediate housing 12 side will be illustrated in thedrawings.

A groove 21 is formed on a rotor axis O-side side surface of each sideseal 7 in this embodiment, and the three linear rollers 10 areaccommodated in the groove 21 of each side seal 7. The rotor 4 ismounted on an eccentric shaft 23 via a rotor bearing 22, and an apexseal 24 which slidably abuts against the inner surface of the rotorhousing 3 is disposed at each apex of the rotor 4. The side seal grooves6 extend to the vicinity of each apex seal 24, and three apex seals areprovided on the side surface 5 of the rotor 4, and the side seal 7 isaccommodated in each of the sides seal grooves 6 (the same arrangementis adopted for the other side 25 of the rotor 4 opposite to the sidesurface 5).

The linear roller 10 accommodated in the groove 21 in each side seal 7has a circular cross-sectional configuration, and three linear rollers10 are provided in this embodiment as described above. The presentinvention is not restricted to the same, and one, two, or four or morelinear rollers 10 may be used. The linear roller 10 in this embodimentis formed of a steel wire made of steel, stainless steel, bearing steel,or the like, but it may be formed of other material. In one example, thediameter of the linear roller 10 is selected from the range of 0.2 mm to1.0 mm, preferably 0.2 mm to 0.5 mm.

In addition, in the rotary engine 1 of this embodiment, an internal gear31 is attached to the rotor 4, the internal gear 31 meshes with a fixedexternal gear 32, a main bearing 33 is fitted over the eccentric shaft23, and oil seal devices 36 and 37 are respectively fitted in twoannular grooves 34 and 35 provided on the side surfaces 5 and 25 of therotor 4.

In the rotary engine 1 thus formed, an end face 41 of the side seal 7projecting from the side seal groove 6 slidably abuts against the sidehousing 2 by being urged by the spring 8 accommodated in the side sealgroove 6, thereby attaining primary gastightness with respect to anengine operating chamber. In addition, the linear rollers 10 in therecess 21 formed on the axis O-side side surface of the side seal 7 areurged against the side wall surface 9 of the side seal groove 6 facingthat side surface by means of the gas pressure and the like of theengine operating chamber, thereby attaining secondary gastightness withrespect to an engine operating chamber.

In the rotary engine 1 in this embodiment, since the linear rollers 10abut against the side wall surface 9, even if the side seal 7 undergoesa very small displacement in the direction of A inside the side sealgroove 6 for some reason or other, the side seal 7 is readily restoredto its original state through the rotation of the linear rollers 10 orthrough the rolling friction or low sliding friction due to the linearcontact of the linear rollers 10 against the side wall surface 9,thereby always maintaining the primary gastightness reliably. In otherwords, the spring 8 is capable of causing the end face 41 of the sideseal 7 to abut against the side housing 2 slidably and with desiredgastightness. Accordingly, in the rotary engine 1, it is possible toreliably prevent the leakage of gases from the engine operating chamber,with the result that the engine efficiency can be enhanced.

In addition, in the present invention, a rotary engine 51 may be formed,as shown in FIGS. 5 to 7. That is, in the rotary engine 51, a thin steelsheet 52 against which the linear rollers 10 abut are secured on theside wall surface 9 of the side seal groove 6 facing the axis O-sideposition of the side seal 7. If the linear rollers 10 are made to abutagainst the thin steel sheet 52 in this manner, the linear rollers 10are prevented from coming into direct contact with the side wall surface9 of the side seal groove 6, so that it is possible to prevent damage,such as indents, from being caused to the side wall surface 9 by thelinear rollers 10. As a result, the return of the side seal 7 to itsoriginal position in the direction of A can be effected more favorably.As the thickness of the thin steel sheet, for example, it is possible to0.05 mm to 0.3 mm, preferably 0.05 mm to 0.1 mm. Also, the thin steelplate 52 is formed of a material such as the stainless steel similar tothat of the linear roller 10.

Although in the above-description the rotary engine is constructed byusing the three linear rollers 10 fitted in parallel, the linear rollers10 may be divided and disposed in parallel. That is, as shown in FIG. 8,a plurality of rows, e.g. three rows as in the above-described example,of a plurality of, i.e., in this example two, linear rollers 62 and 63fitted in series with respective ends facing each other at a position 61are arranged in the groove 21 of the side seal 7, thereby forming therotary engine. If the plurality of linear rollers are arranged in seriesin the groove 21 of each side seal 7, the rotation of the respectivelinear rollers is facilitated, whereby the return of the side seal 7 toits original position in the direction of A can also be effected morefavorably.

In addition, as shown in FIG. 9, an arrangement may be provided suchthat, by using a side seal 65 having a stepped portion 66 formedthereof, the linear rollers 10 are arranged in a recess 67 of thestepped portion 66, thereby forming the rotary engine. In this example,four linear rollers 10 are accommodated between the stepped portion 66and the spring 8, and the four linear rollers 10 are maintained in thedirection of A by means of the stepped portion 66 and the spring 8.

Although in the foregoing examples, three or four linear rollers 10 areprovided, as shown in FIGS. 10 and 11, two linear rollers 10 may bearranged in the groove 21 of the side seal 7, thereby forming the rotaryengine.

Furthermore, although in the rotary engine 51 shown in FIGS. 5 to 7, thelinear rollers 10 are arranged in the groove 21 of the side seal 7 tohold the linear rollers 10 in the direction of A, as shown in FIG. 12,an arrangement may be provided as follows: A plate-like side seal 71 nothaving a groove is disposed in the side seal groove 6, a groove 74 foraccommodating the linear rollers 10 is formed in a thin steel sheet 73secured to the side wall surface 9 of the side seal groove 6, the linearrollers 10 are held in the groove 74 of the thin steel sheet 73 in sucha manner that the linear rollers 10 do not move in the direction of Abut the linear rollers 10 themselves are rotatable, an end face 72 ofthe side seal 71 is made to abut against the side housing 2 by means ofthe spring 8, thereby forming the rotary engine of the presentinvention.

In addition, although, in the example shown in FIG. 8, a series of thelinear rollers 62 and 63 juxtaposed in three rows are formed with thesame length such that the three positions 61 at which their ends faceeach other are made be identical, i.e., overlap, as shown in FIG. 13, anarrangement may be provided as follows: Linear rollers 81, 82, 84, 85,87, and 88 of mutually different lengths are prepared, the linearrollers 81 and 82, the linear rollers 84 and 85, and the linear rollers87 and 88 are arranged in series, respectively, and these three rows arejuxtaposed in the groove of the side seal 7, such that a position 83 ofopposing ends of the linear rollers 81 and 82 and a position 86 ofopposing ends of the linear rollers 84 and 85, as well as the position86 of the opposing ends in the row of the linear rollers 84 and 85 and aposition 89 of opposing ends in the row of the linear rollers 87 and 88,are made to be mutually different. If the positions of opposing ends inthe two adjacent rows of linear rollers are made to be mutuallydifferent, it is possible to further reduce the leakage of gasses fromthe engine operating chamber which pass through gaps between theopposing ends. It should be noted that the positions of the ends are notrestricted to those of this example, and it suffices if the positionsare set to optimum positions in the light of reducing the gas leakage toa minimum.

We claim:
 1. A rotary engine comprising:a rotor housing; a side housingand an intermediate housing arranged on opposite sides of said rotorhousing, respectively: a rotor rotatably disposed in said rotor housingand having two side surfaces, one said side surface facing said sidehousing, another of said side surfaces thereof facing said intermediatehousing, said rotor having an axis; a side seal groove formed on each ofsaid side surfaces of said rotor; side seals disposed in respective sideseal grooves; springs for pressing said side seals against said sidehousing and said intermediate housing, respectively; linear roller meansdisposed along said side seals between said side seals and side wallsurface of said side seal grooves; and a thin metal sheet disposed alonga side wall surface of each said side seal groove facing a rotoraxis-side side surface of said side seal, said linear roller meansabutting said thin metal sheets, respectively.
 2. A rotary engineaccording to claim 1 wherein a groove is formed on a rotor axis-side ofeach said side wall surface of said side seal, said linear roller meansbeing disposed in said grooves of said side seals.
 3. A rotary engineaccording to claim 1 wherein a stepped portion is formed on a rotoraxis-side of each said side wall surface of said side seals, and saidlinear roller means being disposed in a recess of each said steppedportion.
 4. A rotary engine according to claim 1, wherein a groove isformed in said thin metal sheet for accommodating said linear rollermeans.
 5. A rotary engine according to claim 1 wherein said linearroller means includes a plurality of linear rollers arranged parallel toone another.
 6. A rotary engine according to claim 1 wherein said linearroller means includes a plurality of linear rollers arranged end-to-end.7. A rotary engine according to claim 1 wherein said linear roller meansincludes at least first and second rows of flexible linear elongatedrollers, the first row of the linear rollers being arranged parallel tothe second row of the linear rollers, the linear rollers of the firstrow having end faces arranged in end-to-end relation relative to oneanother, the linear rollers of the second row having end faces inend-to-end relation relative to one another, said end faces of thelinear rollers in the first row being spaced from said end faces of thelinear rollers in the second row.
 8. A rotary engine according to claim1 wherein said seal grooves are arcuate and elongated, said linearelongated roller means disposed in said arcuate elongated grooves andextending arcuately in said grooves.
 9. A rotary engine comprising:aside housing; a rotor housing; a rotor disposed in said rotor housingand rotatable about an axis; a side seal groove formed on a side surfaceof said rotor facing said side housing; a side seal disposed in saidside seal groove; a spring for urging said side seal against said sidehousing; linear roller means disposed along said side seal between saidside seal and a side wall surface of said side seal groove; and a thinmetal sheet disposed along said side wall surface of said side sealgroove facing a rotor axis-side side surface of said side seal, saidlinear roller means abutting said thin metal sheet.
 10. A rotary engineaccording to claim 9 wherein said rotor has an axis, a groove formed ona rotor axis-side of a side wall surface of said side seal, said linearroller means being disposed in said groove.
 11. A rotary engineaccording to claim 9, including a stepped portion formed on said rotoraxis-side surface of said side seal, and said linear roller means beingdisposed in a recess of said stepped portion.
 12. A rotary engineaccording to claim 9 wherein a groove is formed in said thin metal sheetfor accommodating said linear roller means.
 13. A rotary engineaccording to claim 9 wherein said linear roller means includes aplurality of linear rollers arranged parallel to one another.
 14. Arotary engine according to claim 9 wherein said linear roller meansincludes a plurality of flexible linear elongated rollers arrangedend-to-end.
 15. A rotary engine according to claim 9 wherein said linearroller means includes at least first and second rows of flexible linearelongated rollers, the first row of the linear rollers being arrangedparallel to the second row of the linear rollers, the linear rollers ofthe first row having end faces in end-to-end relation relative to oneanother, the linear rollers of the second row being arranged inend-to-end relation relative to one another, said end faces of thelinear rollers in the first row being spaced from said end faces of thelinear rollers in the second row.
 16. A rotary engine according to claim9 wherein said seal grooves are arcuate and elongated, said linearelongated roller means disposed in said arcuate elongated grooves andextending arcuately in said grooves.
 17. A rotary engine comprising:arotor housing; a side housing and an intermediate housing arranged onopposite sides of said rotor housing, respectively; a rotor rotatablydisposed in said rotor housing and having an axis and two side surfaces,one said side surface facing said side housing, another of said sidesurfaces thereof facing said intermediate housing; a side seal grooveformed on each of said side surfaces of said rotor; side seals disposedin respective side seal grooves; springs for pressing said side sealsagainst said side housing and said intermediate housing, respectively;and flexible linear elongated roller means disposed along each said sideseal between said side seal and a side wall surface of said seal groove;a thin metal sheet disposed along said side wall surface of said sideseal groove facing a rotor axis-side side surface of said side seal,said linear roller means abutting said thin metal sheet.
 18. A rotaryengine according to claim 17 wherein said side seal is formed with agroove on a rotor axis-side of a side wall surface thereof, said linearroller means being disposed in said groove.
 19. A rotary engineaccording to claim 17 wherein said side seal is formed with a steppedportion on a rotor axis-side of a side wall surface thereof, and saidlinear roller means being disposed in a recess of said stepped portion.20. A rotary engine according to claim 17, including a groove formed insaid thin metal sheet for accommodating said linear roller means.
 21. Arotary engine according to claim 17 wherein said linear roller meansincludes a plurality of flexible linear elongated rollers arrangedparallel to one another.
 22. A rotary engine according to claim 21,including a groove formed in said thin metal sheet for accommodatingsaid linear roller means.
 23. A rotary engine according to claim 17wherein said linear roller means includes a plurality of flexible linearelongated rollers arranged end-to-end.
 24. A rotary engine according toclaim 23, including a groove formed in said thin metal sheet foraccommodating said linear roller means.
 25. A rotary engine according toclaim 17 wherein said linear roller means includes at least first andsecond rows of flexible linear elongated rollers, the first row of thelinear rollers being arranged parallel to the second row of the linearrollers, the linear rollers of the first row having end faces inend-to-end relation relative to one another, the linear rollers of thesecond row having end faces in end-to-end relation relative to oneanother, said end faces of the linear rollers in the first row beingspaced from said end faces of the linear rollers in the second row. 26.A rotary engine according to claim 25, including a groove formed in saidthin metal sheet for accommodating said linear roller means.
 27. Arotary engine according to claim 17 wherein said seal grooves arearcuate and elongated, said flexible linear elongated roller means beingdisposed in said arcuate elongated grooves and extending arcuately insaid grooves.
 28. A rotary engine comprising:a rotor housing; a sidehousing and an intermediate housing arranged on opposite sides of saidrotor housing, respectively; a rotor rotatably disposed in said rotorhousing and having two side surfaces, one said side surface facing saidside housing, another of said side surfaces thereof facing saidintermediate housing; a side seal groove formed on each of said sidesurfaces of said rotor; side seals disposed in respective side sealgrooves; springs for pressing said side seals against said side housingand said intermediate housing, respectively; and flexible linearelongated roller means disposed along each said side seal between saidside seal and a side wall surface of said seal groove, said linearroller means including a plurality of flexible linear elongated rollersarranged end-to-end.
 29. A rotary engine according to claim 28 whereinsaid rotor has an axis, and said side seal is formed with a groove on arotor axis-side of a side wall surface thereof, said linear roller meansbeing disposed in said groove.
 30. A rotary engine according to claim 28wherein said rotor has an axis, and said side seal is formed with astepped portion on a rotor axis-side of a side wall surface thereof, andsaid linear roller means being disposed in a recess of said steppedportion.
 31. A rotary engine according to claim 28 wherein said rotorhas an axis, and a thin metal sheet disposed along said side wallsurface of said side seal groove facing a rotor axis-side side surfaceof said side seal, said linear roller means abutting said thin metalsheet.
 32. A rotary engine according to claim 31, including a grooveformed in said thin metal sheet for accommodating said linear rollermeans.
 33. A rotary engine according to claim 28 wherein said linearroller means includes a plurality of flexible linear elongated rollersarranged parallel to one another.
 34. A rotary engine according to claim33 wherein said rotor has an axis, and a thin metal sheet disposed alongsaid side wall surface of said side seal groove facing a rotor axis-sideside surface of said side seal, said linear roller means abutting saidthin metal sheet.
 35. A rotary engine according to claim 34, including agroove formed in said thin metal sheet for accommodating said linearroller means.
 36. A rotary engine according to claim 28 wherein saidlinear roller means includes at least first and second rows of flexiblelinear elongated rollers, the first row of the linear rollers beingarranged parallel to the second row of the linear rollers, the linearrollers of the first row having end faces in end-to-end relationrelative to one another, the linear rollers of the second row having endfaces in end-to-end relation relative to one another, said end faces ofthe linear rollers in the first row being spaced from said end faces ofthe linear rollers in the second row.
 37. A rotary engine according toclaim 36 wherein said rotor has an axis, and a thin metal sheet disposedalong said side wall surface of said side seal groove facing a rotoraxis-side side surface of said side seal, said linear roller meansabutting said thin metal sheet.
 38. A rotary engine according to claim37, including a groove formed in said thin metal sheet for accommodatingsaid liner roller means.
 39. A rotary engine according to claim 28wherein said seal grooves are arcuate and elongated, said flexiblelinear elongated roller means being disposed in said arcuate elongatedgrooves and extending arcuately in said grooves.
 40. A rotary enginecomprising:a rotor housing; a side housing and an intermediate housingarranged on opposite sides of said rotor housing, respectively; a rotorrotatably disposed in said rotor housing and having two side surfaces,one said side surface facing said side housing, another of said sidesurfaces thereof facing said intermediate housing; a side seal grooveformed on each of said side surfaces of said rotor; side seals disposedin respective side seal grooves; springs for pressing said side sealsagainst said side housing and said intermediate housings, respectively:and flexible linear elongated roller means disposed along each said sideseal between said side seal and a side wall surface of said seal groove,said linear roller means including at least first and second rows offlexible linear elongated rollers, the first row of the linear rollersbeing arranged parallel to the second row of the linear rollers, thelinear rollers of the first row having end faces in end-to-end relationrelative to one another, the linear rollers of the second row having endfaces in end-to-end relation relative to one another, said end faces ofthe linear rollers in the first row being spaced from said end faces ofthe linear rollers in the second row.
 41. A rotary engine according toclaim 40 wherein said rotor has an axis, said side seal being formedwith a groove on a rotor axis-side of a side wall surface thereof, sidelinear roller means being disposed in said groove.
 42. A rotary engineaccording to claim 40 wherein said rotor has an axis, said side seal isformed with a stepped portion on a rotor axis-side of a side wallsurface thereof, and said linear roller means being disposed in a recessof said stepped portion.
 43. A rotary engine according to claim 40wherein said rotor has an axis, and a thin metal sheet disposed alongsaid side wall surface of said side seal groove facing a rotor axis-sideside surface of said side seal, said linear roller means abutting saidthin metal sheet.
 44. A rotary engine according to claim 43, including agroove formed in said thin metal sheet for accommodating said linearroller means.
 45. A rotary engine according to claim 40 wherein saidseal grooves are arcuate and elongated, said flexible linear elongatedroller means being disposed in said arcuate elongated grooves andextending arcuately in said grooves.
 46. A rotary engine comprising:arotor housing having a side surface; a rotor rotatably disposed in saidrotor housing and having an axis; a side seal groove formed on a sidesurface of said rotor facing said side surface of said housing; a sideseal disposed in said side seal groove; a spring for urging said sideseal against said side surface of said housing; flexible linearelongated roller means disposed along said side seal between said sideseal and a side wall surface of said side seal groove; and a thin metalsheet disposed along said side wall surface of said side seal groovefacing a rotor axis-side side surface of said side seal, said linearroller means abutting said thin metal sheet.
 47. A rotary engineaccording to claim 46 wherein said side seal is formed with a groove ona rotor axis-side of a side wall surface thereof, and said linear rollermeans being disposed in said groove of said side seal.
 48. A rotaryengine according to claim 46 wherein said side seal is formed with astepped portion on a rotor axis-side of a side wall surface thereof, andsaid linear roller means being disposed in a recess of said steppedportion.
 49. A rotary engine according to claim 46, including a grooveformed in said thin metal sheet for accommodating said linear rollermeans.
 50. A rotary engine according to claim 46 wherein said linearroller means includes a plurality of flexible linear elongated rollersarranged parallel to one another.
 51. A rotary engine according to claim46 wherein said linear roller means includes a plurality of flexiblelinear elongated rollers arranged end-to-end.
 52. A rotary engineaccording to claim 46 wherein said linear roller means includes at leastfirst and second rows of flexible linear elongated rollers, the firstrow of the linear rollers being arranged parallel to the second row ofthe linear rollers, the linear rollers of the first row having end facesin end-to-end relation relative to one another, the linear rollers ofthe second row having end faces in end-to-end relation relative to oneanother, said end faces of the linear rollers in the first row beingspaced from said end faces of the linear rollers in the second row. 53.A rotary engine according to claim 46 wherein said seal grooves arearcuate and elongated, said flexible linear elongated roller means beingdisposed in said arcuate elongated grooves and extending arcuately insaid grooves.
 54. A rotary engine comprising:a rotor housing having aside surface; a rotor rotatably disposed in said rotor housing; a sideseal groove formed on a side surface of said rotor facing said sidesurface of said housing; a side seal disposed in said side seal groove;a spring for urging said side seal against said side surface of saidhousing; and flexible linear elongated roller means disposed along saidside seal between said side seal and a side wall surface of said sideseal groove, said linear roller means including a plurality of flexiblelinear elongated rollers arranged end-to-end.
 55. A rotary engineaccording to claim 54 wherein said rotor has an axis, said side sealbeing formed with a groove on a rotor axis-side of a side wall surfacethereof, and said linear roller means being disposed in a said groove ofsaid side seal.
 56. A rotary engine according to claim 54 wherein saidrotor has an axis, said side seal is formed with a stepped portion on arotor axis-side of a side wall surface thereof, and said linear rollermeans being disposed in a recess of said stepped portion.
 57. A rotaryengine according to claim 54 wherein said rotor has an axis, and a thinmetal sheet disposed along said side wall surface of said side sealgroove facing a rotor axis-side side surface of said side seal, saidlinear roller means abutting said thin metal sheet.
 58. A rotary engineaccording to claim 57, including a groove formed in said thin metalsheet for accommodating said linear roller means.
 59. A rotary engineaccording to claim 54 wherein said linear roller means includes aplurality of flexible linear elongated rollers arranged parallel to oneanother.
 60. A rotary engine according to claim 59 wherein said rotorhas an axis, and a thin metal sheet disposed along said side wallsurface of said side seal groove facing a rotor axis-side side surfaceof said side seal, said linear roller means abutting said thin metalsheet.
 61. A rotary engine according to claim 60, including a grooveformed in said thin metal sheet for accommodating said linear rollermeans.
 62. A rotary engine according to claim 54 wherein said linearroller means includes at least first and second rows of flexible linearelongated rollers, the first row of the linear rollers being arrangedparallel to the second row of the linear rollers, the linear rollers ofthe first row having end faces in end-to-end relation relative to oneanother, the linear rollers of the second row having end faces inend-to-end relation relative to one another, said end faces of thelinear rollers in the first row being spaced from said end faces of thelinear rollers in the second row.
 63. A rotary engine according to claim54 wherein said seal grooves are arcuate and elongated, said flexiblelinear elongated roller means being disposed in said arcuate elongatedgrooves and extending arcuately in said grooves.
 64. A rotary enginecomprising:a rotor housing having a side surface; a rotor rotatablydisposed in said rotor housing; a side seal groove formed on a sidesurface of said rotor facing said side surface of said housing; a sideseal disposed in said side seal groove; a spring for urging said sideseal against said side surface of said housing; and flexible linearelongated roller means disposed along said side seal between said sideseal and a side wall surface of said side seal groove, said linearroller means including at least first and second rows of flexible linearelongated rollers, the first row of the linear rollers being arrangedparallel to the second row of the linear rollers, the linear rollers ofthe first row having end faces in end-to-end relation relative to oneanother, the linear rollers of the second row having end faces inend-to-end relation relative to one another, said end faces of thelinear rollers in the first row being spaced from said end faces of thelinear rollers in the second row.
 65. A rotary engine according to claim64 wherein said rotor has an axis, and a groove formed on a rotoraxis-side of a side wall surface of said side seal, and said linearroller means being disposed in a said groove of said side seal.
 66. Arotary engine according to claim 64 wherein said rotor has an axis, anda stepped portion formed on a rotor axis-side of a side wall surface ofsaid side seal, and said linear roller means being disposed in a recessof said stepped portion.
 67. A rotary engine according to claim 64wherein said seal grooves are arcuate and elongated, said flexiblelinear elongated roller means being disposed in said arcuate elongatedgrooves and extending arcuately in said grooves.